Force measuring apparatus

ABSTRACT

Force measuring apparatus including an endless body having a first set of force applying elements projecting from the body for applying forces to the body in one axial direction at spaced locations and a second set of force applying elements projecting from the body for applying forces to the body in the opposite axial direction at spaced locations on the body. The force applying elements of one set are in staggered relationship with the force applying elements of the other set to cause flexural stressing of the body between adjacent force applying elements of the two sets. The apparatus also includes means for resiliently supporting a load cell on a base member in both axial and transverse directions relative to the base member so that the load cell resiliently &#39;&#39;&#39;&#39;floats&#39;&#39;&#39;&#39; relative to the base member.

United States Patent:

Shoberg [54] FORCE MEASURING APPARATUS [72] Inventor: Ralph S. Shoberg,Farmington, Mich, [73] Assignee: GSE Incorporated, Detroit, Mich.

[22] Filed: Feb. 25, 1970 [21] App]. No.: 13,942

[52] US. Cl. ..73/l4l A, 177/211 [51] Int. Cl. ..G01l1/22 [58] FieldolSearch ..73/14l A; 177/210,211

[56] References Cited UNITED STATES PATENTS 2,487,595 11/1949 Ruge.........73/141 Ax 2,855,779 10/1958 Zaid..... ....73/88.5 R 3,233,452 2/1966Jones ..73/147 2,536,117 l/1951 Abramson .....73/l41 2,995,034 8/1961Boiten ..73/l41 3,277,718 10/1966 .73/141 X 1451 Jan; 2 5', 1972 FOREIGNPATENTS on APPLlCATlONS 472,669 6/1969 Switzerland ..73/141 PrimaryExaminer-Charles A. Ruehl Anorney--Barnard, McGlynn k Reising [5 7]ABSTRACT Force measuring apparatus including an endless body having afirst set of force applying elements projecting from the body forapplying forces to the body in one axial direction at spaced locationsand a second set of force applying elements projecting from the body forapplying forces to the body in the opposite axial direction at spacedlocations on the body. The force applying elements of one set are instaggered relationship with the force applying elements of the other setto cause flexural stressing of the body between adjacent force applyingelements of thetwo sets. The apparatus also includes means forresiliently supporting a load cell on a base member in both axial andtransverse directions relative to the base member so that the load cellresiliently floats relative to the base member.

34 Claims, 1 1 Drawing Figures z [8 4' [4 84 22 1 l I sak'iw' 3s w x 28-42 m Kovacs ..73/l4l X FORCE MEASURING APPARATUS This invention relatesgenerally 'to force measuring apparatus and is particularly concernedwith the construction of force measuring apparatus particularlysensitive to forces in an axial direction relative to the apparatus butwhich is insensitive to, and is unaffected by, transverse forces actingon the apparatus.

A particular problem in the construction of load cells for themeasurement of axial forces is that of effects of transverse or sideloads, that is, loads in a nonaxial direction which interfere with themeasurement of the axial forces applied to the load cells. Side loads onthe load cell can be introduced due to an imbalance in the applicationof the load, or to frictional forces resulting from the manner in whichthe load cell is supported.

- it is therefore an object of this invention to provide force measuringapparatus that is highly sensitive to axial loads but which is highlyinsensitive to nonaxial loads.

A further object is to provide force measuring apparatus wherein axialforces on the apparatus are distributed over an endless load cell bodyto thereby minimize the effects of nonaxial loads.

Still another object is to provide force measuring apparatus wherein aload cell is resiliently supported in both an axial and transversedirection relative to the base member to eliminate the transmission ofstress between the base member and load cell.

Still another object is to provide force measuring apparatus including aload cell resiliently supported in both an axial and transversedirection with respect to a base member such that the load cell isinsensitive to installation forces and to the shape of the structure onwhich the apparatus is mounted.

The foregoing, and other objects, are achieved by the provision of forcemeasuring apparatus including an endless body with two sets of forceapplying elements projecting therefrom. One set of force applyingelements applies forces in one axial direction relative to the body atspaced locations and the other set of force applying elements applyforces in the opposite axial direction to the body at spaced locationson the body. Force applying elements of one set are staggered withrespect to the force applying elements of the other set so that flexuralstrain is applied to the body between adjacent force applying elementsof the two sets, which strain can be measured by strain gages attachedto the body adjacent the force applying elements in the areas of highstress. In one embodiment of the invention, the endless load cell bodyis reduced in cross section on each side of each of the force applyingelements to concentrate the flexural stresses and strains at the forceapplying elements.

The endless load cell body is mounted between two force applyingmembers. One of the force applying members is engaged with one set offorce applying elements and the other force applying member is engagedwith the other set of force applying elements. One of the force applyingmembers is resiliently supported in a base member by an O-ring receivedin a recess formed in the base member. The force applying member issupported on the elastomeric O-ring in both a transverse and axialdirection so that the load cell, in effect, floats" with respect to thebase member. Accordingly, there is a more nearly uniform transfer offorces between the load cell and base member so that the load cell isinsensitive to installation forces.

Other objects, advantages and features of the invention will becomeapparent from the following description taken in connection with theaccompanying drawings in which:

FIG. 1 is a plan view of force measuring apparatus according to thepresent invention;

FIG. 2 is a sectional view taken on lines 2-2 of F 16.1

FlG. 3 is a plan view of a force or load cell body of the apparatus ofFIGS. 1 and 2;

FIG. 4 is a view taken on line 4-4 of FIG. 3; FIG. 5 is a view similarto FIG. 3 of an alternate construction of load cell body;

FIG. 6 is a view similar to FIG. 4 taken on lines 66 of FlG.

FlG. 7 is schematic diagram of one arrangement of strain gages suitablefor the load cell body of FlGS.-3 and 4;

FIG. 8 is'a plan view of weighting apparatus utilizing the forcemeasuring apparatus of the present invention;

FIG. 9 is a sectional view taken on lines 9-9 of FIG. 8;

FIG. 10 is a perspective view of another embodiment of the invention;and

FIG. 1 l is a view taken on lines l1ll of FIG. 10.

In the apparatus illustrated in FIGS. 1 through 4, reference numeral 2collectively designates force measuring apparatus including an endless,annular body 4 having inner and other peripheral surfaces 6 and 8,respectively, extending between a pair of spaced end surfaces 10 and 12(FIGS. 3 and 4). A first set of force applying elements 14 projects frombody 4 for applying forces to body 4 in one axial direction at spacedlocations on body 4. in the illustrated embodiment, the first set offorce supplying elements 14 includes four force applying elements in theform of axially projecting support legs or pads 14a, 14b, 14c, and 14dwhich are equally spaced on the periphery of the end surface 10. Thesecond set of force applying elements 16 projects from body 4 forapplying forces in the opposite direction to the body at spacedlocations on body 4. The set of force applying elements 16 also includefour equally spacedforce applying elements in the form of axiallyprojecting support pads or legs 16a, 16b, 16c and 16d. The forceapplying elements 14 of the first set are in staggered, or angularlyoffset relationship with the force applying elements 16 of the secondset to cause flexural stressing and straining of the body 4 betweenadjacent force applying elements 14 and 16. For example, as shown inFIG. 3, the four force applying elements 14 are equally spaced from eachother and the four force applying elements 16 are equally spaced 90 fromeach other, but the peripherally adjacent pair of force applyingelements 14a and 16a are located 45 from each other. By applying axialforces to elements 14 in the opposite direction to forces being appliedto elements 16, the body 4 tends to bend around each of the elements 14and 16, the high-stress areas being located on each side of each of theelements 14 and 16.

In FIGS. 1 and 2, a force applying member 18 is engaged with the forceapplying elements 14, and a force applying member 20 is engaged with theforce applying elements 16. Tile force applying member 18 is in the formof a cap having a depending peripheral skirt 19 surrounding the annularload cell body 4. The lower surface 18a of member 18 engages the outerends of the force applying elements 14, and an annular shoulder 19aformed at the junction of the inner surface of skirt 19 and surface 19afor centering the body 4 with respect to member 18. As shown in F168. 1and 2, member 18 is threadedly attached by screws 22 with each of theelements 14.

The force applying member 20 is recessed to define an annular skirt orflange 20a projecting axially upwardly in FIG. 2. The recesses surface39 surrounded by flange 20a engages the force applying elements-16,flange 20a serving to center body 4 relative to member 20. As shown inFIG. 2, member 20 is threadedly attached by screws 24 with each of theelements 16.

The apparatus of FIGS. 1 and 2 further includes a base member 26, andmeans in the form of an O-ring 28 of .elastomeric material resilientlysupports the force applying member 20 on the base member 26. Base member26 is formed with a recess 30 having an endless, axially extendingperipheral wall or shoulder 32 which is circular in the illustratedembodiment. The O-ring 28 is received in recess 30 and projects axiallybeyond the recess 30 and is restrained against radial expansion by thewall 32. Member 20 includes an axially projecting portion 34 which isreceived in the O-ring 28 with its outer periphery engaging the innerperiphery of the O- ring 28. The member 20 also has an annular, radiallyprojecting portion 36 which overlies the axially projecting orprotruding portion of the O-ring 28 such that the force applying member20 is resiliently support on the O-ring 28 in both an axial andtransverse direction with respect to the base member. That is to say,O-ring 28 resiliently supports member 20 against movement in an axialdirection toward the surface of recess 30, and also resiliently centersmember 20, or supports member 20 against movement in a transversedirection in a direction to decrease the space between the outerperiphery of portion 34 and the surface of wall 32.

Member 20 is fonned with axially extending openings 40 for receiving afastener 38. The base member 26 is formed with fastener receivingopenings 42. The fastener 38 comprises a screw having a head portionoverlying the recessed surface 39 of member 20 opposite the base member26 with its shank extending through the opening 40 in loose, nonthreadedengagement with opening 40, and into threaded engagement with theopening 42 in the base member. The opening 40 is of greater diameterthan the shank of screw 38 so that the shank of the screw does notinterfere with the resilient transverse support of the member 20relative to base member 26 provided by ring 28. To further enhance theresilient support of member 20 on base member 26, an O-ring 44 isclamped between the head of each of the screws 38 and the surface 39 ofmember 20.

The base portion 26 is formed with mounting holes 27 for mounting thebase portion onto a support structure which may be, for example, a brakepedal of an automobile for brake testing. An opening 29 is formed in thewall of the base member 26 in alignment with a slot, groove or opening31 in member 20 for receiving electrical lead wires to strain gageswhich may be attached to the end surface of the load cell body 4.

One particular arrangement of strain gages utilizing sixteenconventional resistance strain gages is illustrated in FIGS. 4 and 7.The locations of the sixteen strain gages are indicated by referencecharacters a, b, c, d, e,f, g, h, 1",], k, l, m, n, 0, and

. p in FIG. 3. The strain gages a-p are connected in a conventionalWheatstone bridge circuit as illustrated in FIG. 7 in such a manner thatthe apparatus is insensitive to side forces which might be encounteredif a force is applied to member 18 off center. The output signal throughlines S to a remote point when the Wheatstone bridge circuit of FIG. 7is unbalanced due to flexural stresses on the body 4 is the sameregardless of the point of application of the load on member 18 due tothe arrangement of the diametrically opposed strain gages and overallgage/flexure symmetry.

The O-ring 28 may be of relatively hard elastomeric material having ahardness of 90 or more on a durometer scale. The hardness of the O-ring28 may, of course, vary with the magnitude of the forces to beencountered with the particular apparatus.

FIGS. 5 and 6 illustrate an alternate construction for the endless loadcell body 4 wherein a load cell body 4' is of similar construction withthe load cell body 4 with the exception that notches 46 extend inwardlyfrom the end surface 12 of body 4' on each side of each of the forceapplying members 14 and 16 to reduce the cross section on each side ofeach of the force applying' elements to provide a higher concentrationof flexural stresses at the force applying elements 14 and 16. Theabrupt reduction in cross section at the high-stress areas providesincreased sensitivity or strain per increment of deflection of the body4 about the elements 14 and 16.

FIGS. 8 and 9 illustrate a force measuring apparatus wherein four loadcells 102 supporting a platform of arbitrary shape may be utilized tomeasure the weight distribution of automobiles or other vehicles bymeasuring the force applied to each wheel of the vehicle. The apparatus100 includes a base member 126 and four load cells 102 each of which hasan endless elastomeric member in the form of an O-ring 128 whichresiliently supports the respective load cell 102 in both an axial andtransverse direction relative to the base member 126. A recess 130 isformed in the base member 126 for each load cell 102, the recess havinga circular, axially extending wall 132 with the O-ring 128 received inthe recess and projecting axially beyond the wall 132 but beingrestrained against radial expansion by wall 132. Load cell 102 includesan axially projecting portion 134 whichis received in the O- ring 128with its outer periphery engaging the inner periphery of the O-ring. Theload cell .102 also has a portion 136'overlying the axially projectingportion of the O-ring so that the O- ring supports the load cell 102resiliently against movement in an axial direction toward the surface ofrecess 130 and in a transverse direction against movement oh center withrespect to the wall 132. As in the arrangement of FIGS. 1 and 2,fastener means 138 may be provided for securing the load cell 102 to thebase member 126 against axial separation. The fastener means 138 is inthe form of a screw which has a shank smaller than the opening in theload cell member 134 so that the screw does not interfere with thetransverse resilient support provided by O-ring 128.

A weighing platform 226 overlies the load cell 102 and a downwardlyopening recess 230 is defined on the platform with a circular, axiallyextending wall 232. A second elastomeric O-ring 228 is received in therecess 230, and the load cell includes an upwardly, axially projectingportion 234 which is received in the O-ring 228 with its outer peripheryengaging the inner periphery of the O-ring 228 and with a portion 236underlying the axially projecting portion 228 of the O-ring such thatthe platform is supported on the load cell in both an axial andtransverse direction with respect to the load cell. The resilientlyfloating support of the platform 226 with respect to load cell 102 andof the load cell 102 with respect to base member 126 substantiallyeliminates the effects of any side forces or localized forced due to theflexing or deformation of base 126 or platform 226 on the load cell 102.The result, in a practical sense, being that the input to the flexurering section 236 is independent of the shape or location of the memberapplying load to platform 226 and base 126.

FIG. 10 illustrates another embodiment of the invention wherein theendless load cell body is integrally formed with the load-applyingmembers. FIG. 10 illustrates load-applying apparatus 302 comprising anendless body 304 having inner and outer peripheral surfaces 306 and 308,respectively, extending between a pair of spaced end surfaces 310 and312. A set of force applying elements 314 projects upwardly from surface310 and a set of force applying elements 316 project downwardly fromsurface 312. The force applying elements 314 are integral with a forceapplying member or portion 318, and the force applying elements 316 areintegral with a force applying member or portion 320. The load cell ofFIG. 10 may be formed of tubular stock with cutout portions 315 and 317defining the force applying elements 314 and 316. Elements 314 and 316are in staggered relationship with each other so that axial forcesapplied to the endless body 304 by the force applying elements 314 and316 causes flexure of body 304. Member 320 is integral withan-attachment portion 324 which is internally threaded for securing to asupporting member, and member 318 is integral with an attachment portion326 having an externally threaded stem 328.

While specific embodiments of he invention have been illustrated anddescribed in the foregoing specification and accompanying drawings, itshould be understood that the invention is not limited to the exactconstruction shown but that various alterations in the construction andarrangement of parts is possible without departing from the scope andspirit of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Force measuring apparatus comprising: an endless body having innerand outer peripheral surfaces extending between a pair of spaced endsurfaces; a first set of force applying elements formed integrally onsaid body and projecting axially from one of said end surfaces forapplying forces in one axial direction to said body at spaced locationson said body; a second set of force applying elements formed integrallyon said body and projecting axially from the other of said end surfacesfor applying forces in the opposite axial direction to said body atspaced locations on said body, the force applying elements of said firstset being in staggered relationship withthe force applying elements ofsaid second set to cause flexural, bending stressing'of said bodybetweenadjacent force applying elements of the two sets; afirst force applyingmember engaged with said first set offorce applying elements; a secondforce applying member engaged with said second set of force applyingelements; said first force applying member being in the form of a caphaving a depending peripheral skirt receiving said body; and said secondforce applying member having a recesses surface engaging said second setof force applying elements and an axially projecting peripheral skirtsurrounding said recessed surface.

2. Force measuring apparatus as claimed in claim 1 wherein said body isreduced in cross section on each side of each of said force applyingelements to concentrate the flexural stresses at said force applyingelements.

3. Force measuring apparatus as claimed in claim 1, wherein said firstforce applying member is threadedly attached with said first set offorce applying elements and said second force applying member isthreadedly attached to said second set of force applying members.

4. Force measuring apparatus as claimed in claim 1, further including abase member, and means resilientlysupporting one of said force applyingmembers on said base member.

5. Force measuring apparatus as claimed in claim 6 further including arecess formed in said base member, said means resiliently supportingsaid one force applying member com prising an elastomeric memberreceived in said recess.

6. Force measuring apparatus as claimed in claim 4 wherein said firstforce applying member is threadedly attached with said first set offorce applying elements and said second force applying member isthreadedly attached to said second set of force applying members.

7. Force measuring apparatus comprising: an endless body having innerand outer peripheral surfaces extending between a pair of spaced endsurfaces; a first set of force applying elements projecting from saidbody for applying forces in one axial direction to said body at spacedlocations on said body; a

' second set of force applying elements projecting from said body forapplying forces in the opposite axial direction to said body at spacedlocations on said body; the force applying elements of said first setbeing in staggered relationship with the force applying elements of saidsecond set the cause flexural, bending stressing of said body betweenadjacent force applying elements of the two sets, a first force applyingmember engaged with said first set of force applying elements and asecond force applying member engaged with said second set of forceapplying elements; a base member, means resiliently supporting one ofsaid force applying members on said base member; a recess formed in saidbase member; said means resiliently supporting said one force applyingmember comprising an elastomeric member received in said recess whereinsaid recess has a circular, axially extending wall; and said elastomericmember comprising an O-ring received in said recess and projectingaxially beyond said axially extending wall and restrained against radialexpansion by said axially extending wall.

8. Force measuring apparatus as claimed in claim 7 wherein said oneforce applying member includes an axiallyprojecting.

portion received in said O-ring with its outer periphery engaging theinner periphery of said O-ring, said one force applying member having aportion overlying the axially projecting portion of said O-ring wherebysaid one force applying member is resiliently supported on said O-ringin both an axial and transverse direction with respect to said basemember.

9. Force measuring apparatus as claimed in claim 8 further includingfastener means securing said one force applying member to said basemember against axial separation therefrom.

l0. Force measuring apparatus as claimed in claim 9 wherein said oneforce applying member formed with at least one axially extendingfastener receiving opening and said base member is formed with at leastone fastener receiving head portion overlying the surface of saidone.force applying member opposite said base member, said screw having ashank extending through the opening in saidone force applying member inloose, nonthreaded engagement therewith and into threaded engagementwith the opening in said base member.

ll. Force measuring apparatus as claimed in claim 10 further includingan elastomeric O-ring clamped between the head of said screw and theadjacent surface of said one force applying member.

l2. Force measuring apparatus as claimed in claim ll wherein said firstset of force applying elements-projects axially from one end surface ofsaid body and said second set of force applying elements projectsaxially from the other end surface of said body.

13. Force measuring apparatus as claimed in claim 12 wherein said loadcell body is annular.

14. Force measuring apparatus as claimed in claim 13 wherein said oneforce applying member is screw-threadedly attached to said first set offorce applying elements and said second force applying member isscrew-threadedly attached to said second set of force applying elements.

15. Force measuring apparatus as claimed in claim 7 further including aweighing platform overlying the other of said force applying members,and means resiliently supporting said platform on said other forceapplying member both axially and transversely.

1. Force measuring apparatus as claimed in claim 16 further includingmeans defining a downwardly opening recess on said platform having acircular, axially extending wall, said means resiliently supporting saidplatform comprising an elastomeric O-ring received in said downwardlyopening recess projecting axially beyond said axially extending wall andrestrained against radial expansion by said axially extending wall.

l7. Force measuring apparatus as claimed in claim 16 wherein said otherforce applying member includes an axially projection portion received insaid O-ring with its outer periphery engaging the inner periphery ofsaid O-ring, said other force applying member having a portionunderlying the axially projecting portion of said O-ring whereby saidplatform is supported on said O-ring in both an axial and transversedirection with respect to said other force applying member.

18. Force measuring apparatus comprising: a base member; a load cell;means resiliently supporting said load cell both axially andtransversely on said base member; a recess formed in said base member,said means resiliently supporting said load cell comprising anelastomeric member received in said recess wherein said recess has acircular, axially extending wall, and said elastomeric member comprisingan O-ring received in said recess and projecting axially beyond saidaxially extending wall and restrained against radial expansion by saidaxially extending wall.

[9. Force measuring apparatus as claimed in claim 18 wherein said loadcell includes an axially projecting portion received in said 'O-ringwith its outer periphery engaging the inner periphery of said ()-ring,said load cell having a portion overlying the axially projectingportionof said O-ring whereby said load cell is resiliently supported onsaid Q-ring in both an axial and transverse direction with respect tosaid base member.

20. Force measuring apparatus as claimed in claim 19 further includingfastener means securing said load cell to said base member against axialseparation therefrom.

21. Force measuring apparatus as claimed in claim 20 wherein said loadcell is formed with at least one axially extending, fastener receivingopening; and said base member is formed with at least one fastenerreceiving opening. and said fastener means comprises a screw having ahead portion overlying the surface of said load cell opposite said basemember and a shankcxtending through the opening in said load cell inloose, nonthreaded engagement therewith, and into threaded engagementwith the opening in said base member.

22. Force measuring apparatus as claimed in claim 21 further includingan elastomeric O-ring clamped between the head ofsaid screw and thesurface of said load cell.

23. Force measuring apparatus as claimed in claim 21 wherein said loadcell comprises an endless body having inner and outer peripheralsurfaces extending between a pair of spaced end surfaces; a first set offorce applying elements projecting from said body for applying forces-in one axial direction to said body at spaced locations on said body;and a second set of force applying elements projecting from said bodyfor applying forces in the opposite axial direction to said body atspaced locations on said body; the force applying elements of said firstset being in staggered relationship with the force applying elements ofsaid second set to cause flexural stressing of said body betweenadjacent force applying elements of the two sets.

24. Force measuring apparatus as claimed in claim 23 wherein said bodyis reduced in cross section on each side of each of said force applyingelements to concentrate the flexural stresses at said force applyingelements.

25. A force measuring apparatus as claimed in claim 23 wherein said loadcell further includes a first force applying member engaged with saidfirst set of force applying elements and a second force applying memberengaged with said second set of force applying elements.

26. Force measuring apparatus as claimed in claim 25 wherein said firstforce applying member is threadedly attached with said first set offorce applying elements and said second force applying member isthreadedly attached to said second set of force applying members.

27. Force measuring apparatus as claimed in claim 25 wherein said firstforce applying member is integral with said first set of force applyingelements and said second force applying member is integral with saidsecond of force applying elements.

28. Force measuring apparatus as claimed in claim 19 further including aweighing platform overlying said load cell and means resilientlysupporting said platform on said load cell.

29. Force measuring apparatus as claimed in claim 28 further includingmeans defining a downwardly opening recess on said platformhaving acircular, axially extending wall, said means resiliently supporting saidplatform comprising an elastomeric O-ring received in said downwardlyopening recess and projecting axially beyond said axially extending walland restrained against radial expansion by said axially extending wall.

30. Force measuring apparatus as claimed in claim 29 wherein said loadcell includes an upwardly axially projecting portion received in theO-ring of said platform with its outer periphery engaging the innerperiphery of said O-ring and having a portion underlying the axiallyprojecting portion of said O-ring whereby said platform is supported insaid load cell in both an axial and transverse direction with respect tosaid load cell.

3]. Force measuring apparatus as claimed in claim 30 wherein said loadcell comprises an endless body having inner and outer peripheralsurfaces extending between a pair of spaced end surfaces; a first set offorce applying elements projecting from said body for applying forces inone axial direction to said body at spaced locations on said body; and asecond set of force applying elements projecting from said body forapplying forces in the opposite axial direction to said body at spacedlocations on said body; the force applying elements of said first setbeing in staggered relationship with the force applying elements of saidsecond set to cause flexural stressing of said body between adjacentforce applying elements of the two sets.

32. Force measuring apparatus as claimedin claim 31 wherein wherein saidbody is reduced in cross section on each side of each of said forceapplying elements to concentrate the flexural stresses at said forceapplying elements.

33. Force measuring apparatus as claimed in claim 32 wherein said loadcell further includes a first force a plying member engaged with saidfirst set of force applying e ement and a second force applying memberengaged with said second set of force applying elements.

34. Force measuring apparatus as claimed in claim 33 wherein said firstforce applying member is integral with said first set of force applyingelements and said second force applying member is integral with saidsecond set of force applying elements.

7 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,636,760 Dated January 25, 1972 Inventor(s) Ralph S. Shoberg It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 2, line 5 "weighting" should be weighing-'; column 2, linel4-"other" should be --outer--;- column. 2, line 23 "The" should be -A-;column 2, line 45 "THe" should be The. Column 3, line 1 "support" shouldbe supported--. Column 4, line 57 "he" should be --the-. Column 5, line10 "recesses" should be --recessed--; column 5, line 26 "6" should be4--; column 5, line '44 "the" i should be to. Column .6, line 30 "16"should be -l5-; column 6, line 4() "projection" should be projecting-.Column 7, line 35 after "second" insert -set, Column 8,

line 34 "element" should be elements-.

Signed and sealed this 15th day of August 1972;

(SEAL) Attest;

EDWARD M. FLETCHER, JR- 7 ROBERT GOTTSCHALK Attesting OfficerCommissioner of Patents FORM FO'WSO (10'69) uscoMM-oc 60376-P69 U.S.GOVERNMENT PRINTING OFFlCE I969 O-3i6'334 UNITED STATES PATENT OTTTQECETHICATE OE CORECTION Patent No. Dated January 25, 1972 Inventor(s)Ralph S Shoberg It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 2, line 5 "weighting" should be weighing; column 2, line 14"other" should be outer; column 2, line 23 "The" should be A--; column2, line 45 "THe" should be The-. Column 3, line 1 "support" should be-supported. Column 4, line 57 "he" should be the. Column 5, line 10"recesses" should be recessed--; column 5, line 26 "6" should be -4-;column 5, line 44 "the" should be to. Column 6, line 30 "16" should be--l5-- column 6, line 40 "projection" should be projecting. Column 7,line 35 after "second" insert --set--. Column 8,

line 34 "element" should be elements-.

Signed and sealed this 15th day of August 1972.

(SEAL) Attest;

ROBERT GOTTSCHALK Commissioner of Patents EDWARD M. FLETCHE JR.Attesting Officer FORM PO-1050 (10-69) USCOMM-DC 60376-P69 a u.s.GOVERNMENT PRINTING OFFICE: I969 o3sa-aa4

1. Force measuring apparatus comprising: an endless body having innerand outer peripheral surfaces extending between a pair of spaced endsurfaces; a first set of force applying elements formed integrally onsaid body and projecting axially from one of said end surfaces forapplying forces in one axial direction to said body at spaced locationson said body; a second set of force applying elements formed integrallyon said body and projecting axially from the other of said end surfacesfor applying forces in the opposite axial direction to said body atspaced locations on said body, the force applying elements of said firstset being in staggered relationship with the force applying elements ofsaid second set to cause flexural, bending stressing of said bodybetween adjacent force applying elements of the two sets; a first forceapplying member engaged with said first set of force applying elements;a second force applying member engaged with said second set of forceapplying elements; said first force applying member being in the form ofa cap having a depending peripheral skirt receiving said body; and saidsecond force applying member having a recesses surface engaging saidsecond set of force applying elements and an axially projectingperipheral skirt surrounding said recessed surface.
 2. Force measuringapparatus as claimed in claim 1 wherein said body is reduced in crosssection on each side of each of said force applying elements toconcentrate the flexural stresses at said force applying elements. 3.Force measuring apparatus as claimed in claim 1, wherein said firstforce applying member is threadedly attached with said first set offorce applying elements and said second force applying member isthreadedly attached to said second set of force applying members. 4.Force measuring apparatus as claimed in claim 1, further including abase member, and means resiliently supporting one of said force applyingmembers on said base member.
 5. Force measuring apparatus as claimed inclaim 6 further including a recess formed iN said base member, saidmeans resiliently supporting said one force applying member comprisingan elastomeric member received in said recess.
 6. Force measuringapparatus as claimed in claim 4 wherein said first force applying memberis threadedly attached with said first set of force applying elementsand said second force applying member is threadedly attached to saidsecond set of force applying members.
 7. Force measuring apparatuscomprising: an endless body having inner and outer peripheral surfacesextending between a pair of spaced end surfaces; a first set of forceapplying elements projecting from said body for applying forces in oneaxial direction to said body at spaced locations on said body; a secondset of force applying elements projecting from said body for applyingforces in the opposite axial direction to said body at spaced locationson said body; the force applying elements of said first set being instaggered relationship with the force applying elements of said secondset the cause flexural, bending stressing of said body between adjacentforce applying elements of the two sets, a first force applying memberengaged with said first set of force applying elements and a secondforce applying member engaged with said second set of force applyingelements; a base member, means resiliently supporting one of said forceapplying members on said base member; a recess formed in said basemember; said means resiliently supporting said one force applying membercomprising an elastomeric member received in said recess wherein saidrecess has a circular, axially extending wall; and said elastomericmember comprising an O-ring received in said recess and projectingaxially beyond said axially extending wall and restrained against radialexpansion by said axially extending wall.
 8. Force measuring apparatusas claimed in claim 7 wherein said one force applying member includes anaxially projecting portion received in said O-ring with its outerperiphery engaging the inner periphery of said O-ring, said one forceapplying member having a portion overlying the axially projectingportion of said O-ring whereby said one force applying member isresiliently supported on said O-ring in both an axial and transversedirection with respect to said base member.
 9. Force measuring apparatusas claimed in claim 8 further including fastener means securing said oneforce applying member to said base member against axial separationtherefrom.
 10. Force measuring apparatus as claimed in claim 9 whereinsaid one force applying member is formed with at least one axiallyextending fastener receiving opening and said base member is formed withat least one fastener receiving opening, and said fastener meanscomprises a screw having a head portion overlying the surface of saidone force applying member opposite said base member, said screw having ashank extending through the opening in said one force applying member inloose, nonthreaded engagement therewith and into threaded engagementwith the opening in said base member.
 11. Force measuring apparatus asclaimed in claim 10 further including an elastomeric O-ring clampedbetween the head of said screw and the adjacent surface of said oneforce applying member.
 12. Force measuring apparatus as claimed in claim11 wherein said first set of force applying elements projects axiallyfrom one end surface of said body and said second set of force applyingelements projects axially from the other end surface of said body. 13.Force measuring apparatus as claimed in claim 12 wherein said load cellbody is annular.
 14. Force measuring apparatus as claimed in claim 13wherein said one force applying member is screw-threadedly attached tosaid first set of force applying elements and said second force applyingmember is screw-threadedly attached to said second set of force applyingelements.
 15. Force measuring apparatus as claimed in claim 7 furtherincluding a weighing platform overlying the other of said force applYingmembers, and means resiliently supporting said platform on said otherforce applying member both axially and transversely.
 16. Force measuringapparatus as claimed in claim 16 further including means defining adownwardly opening recess on said platform having a circular, axiallyextending wall, said means resiliently supporting said platformcomprising an elastomeric O-ring received in said downwardly openingrecess projecting axially beyond said axially extending wall andrestrained against radial expansion by said axially extending wall. 17.Force measuring apparatus as claimed in claim 16 wherein said otherforce applying member includes an axially projection portion received insaid O-ring with its outer periphery engaging the inner periphery ofsaid O-ring, said other force applying member having a portionunderlying the axially projecting portion of said O-ring whereby saidplatform is supported on said O-ring in both an axial and transversedirection with respect to said other force applying member.
 18. Forcemeasuring apparatus comprising: a base member; a load cell; meansresiliently supporting said load cell both axially and transversely onsaid base member; a recess formed in said base member, said meansresiliently supporting said load cell comprising an elastomeric memberreceived in said recess wherein said recess has a circular, axiallyextending wall, and said elastomeric member comprising an O-ringreceived in said recess and projecting axially beyond said axiallyextending wall and restrained against radial expansion by said axiallyextending wall.
 19. Force measuring apparatus as claimed in claim 18wherein said load cell includes an axially projecting portion receivedin said O-ring with its outer periphery engaging the inner periphery ofsaid O-ring, said load cell having a portion overlying the axiallyprojecting portion of said O-ring whereby said load cell is resilientlysupported on said O-ring in both an axial and transverse direction withrespect to said base member.
 20. Force measuring apparatus as claimed inclaim 19 further including fastener means securing said load cell tosaid base member against axial separation therefrom.
 21. Force measuringapparatus as claimed in claim 20 wherein said load cell is formed withat least one axially extending, fastener receiving opening; and saidbase member is formed with at least one fastener receiving opening, andsaid fastener means comprises a screw having a head portion overlyingthe surface of said load cell opposite said base member and a shankextending through the opening in said load cell in loose, nonthreadedengagement therewith, and into threaded engagement with the opening insaid base member.
 22. Force measuring apparatus as claimed in claim 21further including an elastomeric O-ring clamped between the head of saidscrew and the surface of said load cell.
 23. Force measuring apparatusas claimed in claim 21 wherein said load cell comprises an endless bodyhaving inner and outer peripheral surfaces extending between a pair ofspaced end surfaces; a first set of force applying elements projectingfrom said body for applying forces in one axial direction to said bodyat spaced locations on said body; and a second set of force applyingelements projecting from said body for applying forces in the oppositeaxial direction to said body at spaced locations on said body; the forceapplying elements of said first set being in staggered relationship withthe force applying elements of said second set to cause flexuralstressing of said body between adjacent force applying elements of thetwo sets.
 24. Force measuring apparatus as claimed in claim 23 whereinsaid body is reduced in cross section on each side of each of said forceapplying elements to concentrate the flexural stresses at said forceapplying elements.
 25. A force measuring apparatus as claimed in claim23 wherein said load cell further includes a first force applying memberengageD with said first set of force applying elements and a secondforce applying member engaged with said second set of force applyingelements.
 26. Force measuring apparatus as claimed in claim 25 whereinsaid first force applying member is threadedly attached with said firstset of force applying elements and said second force applying member isthreadedly attached to said second set of force applying members. 27.Force measuring apparatus as claimed in claim 25 wherein said firstforce applying member is integral with said first set of force applyingelements and said second force applying member is integral with saidsecond set of force applying elements.
 28. Force measuring apparatus asclaimed in claim 19 further including a weighing platform overlying saidload cell and means resiliently supporting said platform on said loadcell.
 29. Force measuring apparatus as claimed in claim 28 furtherincluding means defining a downwardly opening recess on said platformhaving a circular, axially extending wall, said means resilientlysupporting said platform comprising an elastomeric O-ring received insaid downwardly opening recess and projecting axially beyond saidaxially extending wall and restrained against radial expansion by saidaxially extending wall.
 30. Force measuring apparatus as claimed inclaim 29 wherein said load cell includes an upwardly axially projectingportion received in the O-ring of said platform with its outer peripheryengaging the inner periphery of said O-ring and having a portionunderlying the axially projecting portion of said O-ring whereby saidplatform is supported in said load cell in both an axial and transversedirection with respect to said load cell.
 31. Force measuring apparatusas claimed in claim 30 wherein said load cell comprises an endless bodyhaving inner and outer peripheral surfaces extending between a pair ofspaced end surfaces; a first set of force applying elements projectingfrom said body for applying forces in one axial direction to said bodyat spaced locations on said body; and a second set of force applyingelements projecting from said body for applying forces in the oppositeaxial direction to said body at spaced locations on said body; the forceapplying elements of said first set being in staggered relationship withthe force applying elements of said second set to cause flexuralstressing of said body between adjacent force applying elements of thetwo sets.
 32. Force measuring apparatus as claimed in claim 31 whereinsaid body is reduced in cross section on each side of each of said forceapplying elements to concentrate the flexural stresses at said forceapplying elements.
 33. Force measuring apparatus as claimed in claim 32wherein said load cell further includes a first force applying memberengaged with said first set of force applying element and a second forceapplying member engaged with said second set of force applying elements.34. Force measuring apparatus as claimed in claim 33 wherein said firstforce applying member is integral with said first set of force applyingelements and said second force applying member is integral with saidsecond set of force applying elements.